Introduce a new IOMMUFD_CMD_VCMDQ_ALLOC ioctl for user space to allocate a vCMDQ for a vIOMMU object. Simply increase the refcount of the vIOMMU.
Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- drivers/iommu/iommufd/iommufd_private.h | 2 + include/uapi/linux/iommufd.h | 41 +++++++++++ drivers/iommu/iommufd/main.c | 6 ++ drivers/iommu/iommufd/viommu.c | 94 +++++++++++++++++++++++++ 4 files changed, 143 insertions(+)
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 79160b039bc7..b974c207ae8a 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -611,6 +611,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd); void iommufd_viommu_destroy(struct iommufd_object *obj); int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd); void iommufd_vdevice_destroy(struct iommufd_object *obj); +int iommufd_vcmdq_alloc_ioctl(struct iommufd_ucmd *ucmd); +void iommufd_vcmdq_destroy(struct iommufd_object *obj);
#ifdef CONFIG_IOMMUFD_TEST int iommufd_test(struct iommufd_ucmd *ucmd); diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index cc90299a08d9..06a763fda47f 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -56,6 +56,7 @@ enum { IOMMUFD_CMD_VDEVICE_ALLOC = 0x91, IOMMUFD_CMD_IOAS_CHANGE_PROCESS = 0x92, IOMMUFD_CMD_VEVENTQ_ALLOC = 0x93, + IOMMUFD_CMD_VCMDQ_ALLOC = 0x94, };
/** @@ -1147,4 +1148,44 @@ struct iommu_veventq_alloc { __u32 __reserved; }; #define IOMMU_VEVENTQ_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VEVENTQ_ALLOC) + +/** + * enum iommu_vcmdq_type - Virtual Command Queue Type + * @IOMMU_VCMDQ_TYPE_DEFAULT: Reserved for future use + */ +enum iommu_vcmdq_type { + IOMMU_VCMDQ_TYPE_DEFAULT = 0, +}; + +/** + * struct iommu_vcmdq_alloc - ioctl(IOMMU_VCMDQ_ALLOC) + * @size: sizeof(struct iommu_vcmdq_alloc) + * @flags: Must be 0 + * @viommu_id: Virtual IOMMU ID to associate the virtual command queue with + * @type: One of enum iommu_vcmdq_type + * @index: The logical index to the virtual command queue per virtual IOMMU, for + * a multi-queue model + * @out_vcmdq_id: The ID of the new virtual command queue + * @addr: Base address of the queue memory in the guest physical address space + * @length: Length of the queue memory in the guest physical address space + * + * Allocate a virtual command queue object for a vIOMMU-specific HW-accelerated + * feature that can access a guest queue memory described by @addr and @length. + * It's suggested for VMM to back the queue memory using a single huge page with + * a proper alignment for its contiguity in the host physical address space. The + * call will fail, if the queue memory is not contiguous in the physical address + * space. Upon success, its underlying physical pages will be pinned to prevent + * VMM from unmapping them in the IOAS, until the virtual CMDQ gets destroyed. + */ +struct iommu_vcmdq_alloc { + __u32 size; + __u32 flags; + __u32 viommu_id; + __u32 type; + __u32 index; + __u32 out_vcmdq_id; + __aligned_u64 addr; + __aligned_u64 length; +}; +#define IOMMU_VCMDQ_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VCMDQ_ALLOC) #endif diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 2b9ee9b4a424..ac51d5cfaa61 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -303,6 +303,7 @@ union ucmd_buffer { struct iommu_ioas_map map; struct iommu_ioas_unmap unmap; struct iommu_option option; + struct iommu_vcmdq_alloc vcmdq; struct iommu_vdevice_alloc vdev; struct iommu_veventq_alloc veventq; struct iommu_vfio_ioas vfio_ioas; @@ -358,6 +359,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { IOCTL_OP(IOMMU_IOAS_UNMAP, iommufd_ioas_unmap, struct iommu_ioas_unmap, length), IOCTL_OP(IOMMU_OPTION, iommufd_option, struct iommu_option, val64), + IOCTL_OP(IOMMU_VCMDQ_ALLOC, iommufd_vcmdq_alloc_ioctl, + struct iommu_vcmdq_alloc, length), IOCTL_OP(IOMMU_VDEVICE_ALLOC, iommufd_vdevice_alloc_ioctl, struct iommu_vdevice_alloc, virt_id), IOCTL_OP(IOMMU_VEVENTQ_ALLOC, iommufd_veventq_alloc, @@ -501,6 +504,9 @@ static const struct iommufd_object_ops iommufd_object_ops[] = { [IOMMUFD_OBJ_IOAS] = { .destroy = iommufd_ioas_destroy, }, + [IOMMUFD_OBJ_VCMDQ] = { + .destroy = iommufd_vcmdq_destroy, + }, [IOMMUFD_OBJ_VDEVICE] = { .destroy = iommufd_vdevice_destroy, }, diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c index a65153458a26..02a111710ffe 100644 --- a/drivers/iommu/iommufd/viommu.c +++ b/drivers/iommu/iommufd/viommu.c @@ -170,3 +170,97 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd) iommufd_put_object(ucmd->ictx, &viommu->obj); return rc; } + +void iommufd_vcmdq_destroy(struct iommufd_object *obj) +{ + struct iommufd_vcmdq *vcmdq = + container_of(obj, struct iommufd_vcmdq, obj); + struct iommufd_viommu *viommu = vcmdq->viommu; + + if (viommu->ops->vcmdq_destroy) + viommu->ops->vcmdq_destroy(vcmdq); + iopt_unpin_pages(&viommu->hwpt->ioas->iopt, vcmdq->addr, vcmdq->length); + refcount_dec(&viommu->obj.users); +} + +int iommufd_vcmdq_alloc_ioctl(struct iommufd_ucmd *ucmd) +{ + struct iommu_vcmdq_alloc *cmd = ucmd->cmd; + struct iommufd_viommu *viommu; + struct iommufd_vcmdq *vcmdq; + struct page **pages; + int max_npages, i; + dma_addr_t end; + int rc; + + if (cmd->flags || cmd->type == IOMMU_VCMDQ_TYPE_DEFAULT) + return -EOPNOTSUPP; + if (!cmd->addr || !cmd->length) + return -EINVAL; + if (check_add_overflow(cmd->addr, cmd->length - 1, &end)) + return -EOVERFLOW; + + max_npages = DIV_ROUND_UP(cmd->length, PAGE_SIZE); + pages = kcalloc(max_npages, sizeof(*pages), GFP_KERNEL); + if (!pages) + return -ENOMEM; + + viommu = iommufd_get_viommu(ucmd, cmd->viommu_id); + if (IS_ERR(viommu)) { + rc = PTR_ERR(viommu); + goto out_free; + } + + if (!viommu->ops || !viommu->ops->vcmdq_alloc) { + rc = -EOPNOTSUPP; + goto out_put_viommu; + } + + /* Quick test on the base address */ + if (!iommu_iova_to_phys(viommu->hwpt->common.domain, cmd->addr)) { + rc = -ENXIO; + goto out_put_viommu; + } + + /* The underlying physical pages must be pinned in the IOAS */ + rc = iopt_pin_pages(&viommu->hwpt->ioas->iopt, cmd->addr, cmd->length, + pages, 0); + if (rc) + goto out_put_viommu; + + /* Validate if the underlying physical pages are contiguous */ + for (i = 1; i < max_npages && pages[i]; i++) { + if (page_to_pfn(pages[i]) == page_to_pfn(pages[i - 1]) + 1) + continue; + rc = -EFAULT; + goto out_unpin; + } + + vcmdq = viommu->ops->vcmdq_alloc(viommu, cmd->type, cmd->index, + cmd->addr, cmd->length); + if (IS_ERR(vcmdq)) { + rc = PTR_ERR(vcmdq); + goto out_unpin; + } + + vcmdq->viommu = viommu; + refcount_inc(&viommu->obj.users); + vcmdq->addr = cmd->addr; + vcmdq->ictx = ucmd->ictx; + vcmdq->length = cmd->length; + cmd->out_vcmdq_id = vcmdq->obj.id; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + iommufd_object_abort_and_destroy(ucmd->ictx, &vcmdq->obj); + else + iommufd_object_finalize(ucmd->ictx, &vcmdq->obj); + goto out_put_viommu; + +out_unpin: + iopt_unpin_pages(&viommu->hwpt->ioas->iopt, cmd->addr, cmd->length); +out_put_viommu: + iommufd_put_object(ucmd->ictx, &viommu->obj); +out_free: + kfree(pages); + return rc; +}